Objective: To determine the survival duration of stage I-III breast cancer patients, and to determine prognostic factors for overall survival and disease-free survival in stage I to III breast cancer patients treated with surgery and adjuvant therapy.
Material and Method: This retrospective cohort study was conducted by reviewing 166 files of stage I-III breast cancer patients treated with surgery and adjuvant therapy in the Oncology Unit, Department of Medicine, Rajavithi Hospital from January 1st 1998 to December 31st 2007.
Results: There were 166 patients whose median age was 48 years. The 5-year overall survival rates for stage I, stage II and stage III were 100.0%, 89.0% and 80.8% respectively (p = 0.11). Multivariate analysis showed that pathological lymph node pN2 status was a significant poor prognostic factor for overall survival (HR = 4.32, 95%CI 1.24-15.04; p = 0.022). The one-, three- and five-year disease-free survival (DFS) rates were 96.7%, 81.4% and 76.7% respectively. Multivariate analysis revealed that pathological pN2 (HR = 4.43, 95%CI 1.44-13.57; p = 0.009), pN3 (HR = 5.16, 95%CI 1.54-17.30; p = 0.008) and progesterone receptor status negative (HR = 5.53, 95%CI 1.85-16.59; p = 0.002) were poor prognostic factors for disease-free survival.
Conclusion: The most important prognostic factor affecting disease-free survival and overall survival of stage I-III breast cancer patients was axillary lymph node metastasis. Progesterone receptor status negative influenced disease relapse. Patients with multiple unfavorable risk factors such as lymph node metastasis and progesterone receptor status negative showed poor DFS, and therefore more aggressive adjuvant chemotherapy is required for these patients.

Keywords: Breast cancer, Survival, Prognostic factor